Boxing guru Monty Betham says the title bout was marred by over-officiating in Joshua's favour.
Joseph Parker's promoter David Higgins says his team have no complaints with the result against Anthony Joshua, although he did draw attention to the very wide scorecards and a referee who many observers believe interfered more than he should have.
"You must be gracious in defeat," Higgins said in the aftermath of a dramatic night at the Principality Stadium. "For all our team, there is a feeling we did our best and our chins are up. Anthony Joshua won the fight. I think it was probably closer than the cards showed."
The American and British judges scored it 118-110 to Joshua, the New Zealand judge Ian Scott feeling it was more one-sided than that, scoring it 119-109.
The world title boxing fight between Joseph Parker and Anthony Joshua held at Principality Stadium, Cardiff. 31 March 2018 New Zealand Herald Photograph by Dean Purcell.
It was Kiwi Parker's first professional defeat in 25 fights, while Joshua, who takes over Parker's WBO belt, moves to 21-0. This was the first time he had been taken the distance.
Parker, who struggled to get behind Joshua's ramrod jab, did best immediately after being tagged. But when he went on the charge and brawled, Italian referee Giuseppe Quartarone got in between them.
Regardless, both men often hit after the break, and in particular Joshua, who at one point landed with an uppercut when Parker had stopped fighting.
"It's interesting, the UK television commentators say the Italian referee kept pulling Joe out when he got in, and did us no favours," Higgins said. "His English wasn't very good.
"There's not a funeral, in fact the fans will probably demand a re-match. You live and learn – Joseph Parker, he's not a sook. You have to remember, Wladimir Klitschko lost three times before his 10-year reign. He learned from that. I think we learned the Joshua is a good boxer and can go the distance.
Anthony Joshua ducks a left hook from Joseph Parker. Photo / Dean Purcell
"When Joe was brawling there were hints of Joe finishing it, but the referee kept separating it.
"A lot of his opponents have been intimidated and [veteran promoter Bob] Arum made the comment that Joe was not intimidated. And Joshua clearly took it very seriously – that's the fittest we've ever seen him.
"There was enough in that fight to be a proper re-match and with a different referee there might be a different result.
"I don't know what it would take to put Joseph down – he's still never been dropped."
Asked what Parker plans were now, Higgins said: "It's up to him, but I sized him up and I was impressed because some people get broken. He was very philosophical.
Joseph Parker on the ropes. Photo / Dean Purcell
"There might be the odd chorus of commentators who say 'change your trainer, change your promoter', but Joseph won't be one of them because he knows everyone did their best, including him."
The show was everything Joshua's promoter Eddie Hearn promised. Higgins said: "It was amazing to be a part of. It was epic - I've never seen anything like it."
"He boxed better than I thought he would," Higgins added of Joshua's technical style.
To get the day's top sports stories in your inbox, sign up to our newsletter here
